CN104074487B - Drawing type packer - Google Patents

Abstract

The invention discloses a drag-type packer, which belongs to the technical field of tight oil and gas reservoir exploitation in oilfields, and aims to solve the problems of existing packers such as sand sticking, unreliable setting, and difficulty in completing multi-stage fracturing in one trip. And design. It includes a joint, a reversing mechanism and a sealing mechanism connected sequentially from bottom to top; the reversing mechanism includes a guide head, a centralizing block, a centralizing block spring, slips and a slip spring, and the guiding head is threaded on the guiding head seat, and the centralizing The block and the spring of the centralizing block are installed on the seat of the centralizing block, the guide head seat and the seat of the centralizing block are screwed together, the slips and the spring of the slip are installed on the seat of the slip, and the seat of the slip is connected with the thread of the seat of the centralizing block; the sealing mechanism includes a rubber tube , the cone and the center pipe, the rubber sleeve is set on the center pipe, the center pipe is threadedly connected with the cone, and the cone is connected with the reversing mechanism. The present invention realizes the setting and unsealing of the packer by changing the track by lifting and lowering the pipe string. The operation is simple, the setting is reliable, and the multi-stage fracturing is realized in one trip of the pipe string.

Description

drag packer

technical field

The invention relates to a special tool for oil and gas well fracturing in an oil field, in particular to a dragging packer.

Background technique

With the continuous development of various complex trajectory wells, ultra-long horizontal wells, and sidetracked wells in oil fields, new issues have been proposed for oil well fracturing technology. The existing packers mainly have the following disadvantages in the oil field fracturing process: first, sand bridges are easily formed after fracturing, causing sand jams; second, the setting seal caused by oil pipe pressure fluctuations is unreliable; It is difficult to achieve multi-stage (for example, more than 10 stages) fracturing in one string because of its poor tear resistance.

Contents of the invention

An object of the present invention is to provide a drag-type packer with simple operation, reliable setting and multi-stage fracturing in one trip.

Another object of the present invention is to propose a dragging packer that solves the problem of the packer being stuck by sand.

For reaching this purpose, the present invention adopts following technical scheme:

The invention provides a drag-type packer, which includes a joint, a reversing mechanism and a sealing mechanism connected sequentially from bottom to top;

The reversing mechanism includes a guide head, a centralizing block, a centralizing block spring, slips and slip springs, the guiding head is screwed on the guiding head seat, and the centralizing block and the centralizing block spring are installed on the centralizing block seat Above, the guide head seat and the centralizing block seat are threaded, the slips and the slip spring are mounted on the slip seat, and the slip seat and the centralizing block seat are threaded;

The sealing mechanism includes a rubber sleeve, a cone and a central tube, the rubber sleeve is sleeved on the central tube, the lower end of the central tube is screwed to the cone, and the cone is connected to the reversing Institutional connections.

Preferably, the central tube includes an outer central tube and an inner central tube, the rubber sleeve includes an outer rubber sleeve and an inner rubber sleeve, and the outer rubber sleeve is sleeved on the outer central tube and is close to the cone The top end of the body, the inner rubber sleeve is sleeved on the inner central tube and connected with the outer central tube.

Preferably, the upper end of the joint is connected to the guide head seat through the central pipe, and the slips are arranged close to the bottom end of the cone.

Preferably, the dragging packer also includes a backwash mechanism, the backwash mechanism includes a valve cover, a spring and a ball valve, the valve cover is connected to the ball valve through the spring, and the valve The cap, the spring and the ball valve are all disposed within the inner base tube.

Preferably, the outer rubber tube has a sealing part and a supporting part, and an inner ring of the outer rubber tube is arranged between the sealing part and the outer central tube.

The beneficial effects of the present invention are:

(1) The present invention provides a dragging packer. In the oil field production process, by connecting the dragging packer to the sand blaster and the pipe string, when the dragging packer is put downhole , the guide head is located at the short track of the circulating guide rail. When the dragging packer is lowered to the predetermined depth, the string is lifted up, and the dragging packer is ready to be set. After that, the string is lowered and thrust is applied. The guide head is located At the long track of the circulating guide rail, the slips are stretched and bit the casing wall, and the pipe string is pushed down continuously, the rubber sleeve is compressed, making the diameter of the rubber sleeve larger, and the sealing of the annular space of the sealing oil sleeve is completed. After the operation is completed , lift the string, the central pipe of the drag packer goes up, the thrust of the rubber tube is canceled and restored, and the slip recovery is completed and unsealed. The invention realizes the setting and unsealing of the drag packer by changing the track by lifting and lowering the pipe string, which not only has simple operation and reliable setting, but also realizes multi-stage fracturing in one pipe string.

(2) The drag packer is also equipped with a backwashing mechanism. After the operation is completed, the backwashing mechanism can enable the oil casing to establish a one-way channel to realize the function of backwashing, which solves the problem of the existing packer. Sand bridges are formed during fracturing and are stuck by sand.

(3) The outer rubber tube has a sealing part and a supporting part, and an inner ring of the outer rubber tube is arranged between the sealing part and the outer central tube. This structure can not only ensure the sealing performance of the rubber tube, but also ensure the high pressure resistance performance of the rubber tube.

Description of drawings

Fig. 1 is a sectional view of a dragging packer provided by Embodiment 1 of the present invention;

Fig. 2 is a cross-sectional view of the structure of the upper half of the drag packer provided by Embodiment 1 of the present invention;

Fig. 3 is a cross-sectional view of the structure of the lower half of the dragging packer provided by Embodiment 1 of the present invention.

In the figure, 1, joint; 2, reversing mechanism; 21, guide head; 22, righting block; 23, righting block spring; 24, slips; 25, slip spring; 26, guiding head seat; Seat; 28, slip seat; 3, sealing mechanism; 31, cone; 32, outer center tube; 33, inner center tube; 34, outer rubber tube; 341, sealing part; 342, support part; 35, inner rubber 4. Backwash well mechanism; 41. Bonnet; 42. Spring; 43. Ball valve.

detailed description

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

Embodiment one:

This embodiment provides a dragging packer. The up and down positions described herein are for the use state of the dragging packer after entering the oil well. To be precise, the dragging packer The connector position of the device is down.

The structure of the dragging packer is shown in Figures 1-3, which includes a joint 1, a reversing mechanism 2 and a sealing mechanism 3 connected in sequence from bottom to top.

As shown in Figure 3, the reversing mechanism 2 includes a guide head 21, a righting block 22, a righting block spring 23, a slip 24 and a slip spring 25, the guide head 21 is threaded on the guide head seat 26, the righting block 22 and the righting block The block spring 23 is installed on the righting block seat 27, the guide head seat 26 and the righting block seat 27 are threaded, the slips 24 and the slip spring 25 are installed on the slip seat 28, and the slip seat 28 and the righting block seat 27 are threaded , the above structure realizes the function of setting and reversing.

As shown in FIG. 2 , the sealing mechanism 3 includes a rubber sleeve, a cone 31 and a central tube. The rubber sleeve is sleeved on the central tube.

The central tube includes an outer central tube 32 and an inner central tube 33. The rubber tube includes an outer rubber tube 34 and an inner rubber tube 35. The outer rubber tube 34 is sleeved on the outer central tube 32 and is arranged close to the top of the cone 31. The inner rubber tube The barrel 35 is sheathed on the inner central tube 33 and connected to the outer central tube 32 .

The upper end of the joint 1 is connected with the guide head seat 26 through the center pipe, and the slips 24 are arranged close to the bottom end of the cone 31 .

In the oil field production process, by connecting the dragging packer to the sand blaster and the pipe string, when the dragging packer is put downhole, the guide head 21 is located at the short track of the circulating guide rail, when the dragging packer The packer is lowered to the predetermined depth, and the pipe string is raised by 0.5m (not including the expansion and contraction of the pipe string). At the long track of the guide rail, the slips 24 are stretched and grip the casing wall, and the pipe string is pushed down continuously, and the outer rubber sleeve 34 and the inner rubber sleeve 35 are both compressed, so that the diameters of the outer rubber sleeve 34 and the inner rubber sleeve 35 become smaller. Large, the sealing of the annular space of the oil jacket is completed. After the operation is completed, the pipe string is lifted up, and the outer center pipe 32 and inner center pipe 33 of the drag packer go up accordingly, and the outer rubber sleeve 34 and the inner rubber sleeve The thrust of 35 was withdrawn and recovered, and the recovery of slip 24 was completed and unblocked. The invention realizes the setting and unsealing of the drag packer by changing the track by lifting and lowering the pipe string. The operation is simple, the setting is reliable, and the multi-stage fracturing is realized in one trip of the pipe string.

Preferably, the drag packer in this embodiment also includes a backwash mechanism 4, the backwash mechanism 4 includes a valve cover 41, a spring 42 and a ball valve 43, the valve cover 41 is connected to the ball valve 43 through the spring 42, and The valve cover 41, the spring 42 and the ball valve 43 are all arranged in the inner center pipe 33, so that a one-way passage is formed between the oil sleeves. After the operation is completed, the backwashing mechanism can make the oil casing establish a one-way channel to realize the function of backwashing, which solves the problem that the existing packer is stuck by sand due to the formation of sand bridges during the fracturing process.

The outer rubber tube 34 has two parts: a sealing part 341 and a supporting part 342. The inner ring 36 of the outer rubber tube is arranged between the sealing part 341 and the outer central tube 32. This structure can not only ensure the sealing performance of the rubber tube, but also ensure the Anti-high pressure performance.

The above describes the technical principles of the present invention in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present invention, and cannot be construed as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation modes of the present invention without creative effort, and these modes will all fall within the protection scope of the present invention.

Claims (4)

1. a drawing type packer, it is characterised in that: the joint (1) that includes being sequentially connected with from top to bottom, Changement (2) and sealing mechanism (3)；

Described changement (2) include guide head (21), wiper block (22), wiper block spring (23), Slips (24) and slips spring (25), described guide head (21) is threaded in guiding headstock (26), Described wiper block (22) and described wiper block spring (23) are arranged on righting block (27), described in lead Threaded to headstock (26) and described righting block (27), described slips (24) and described slips bullet Spring (25) is arranged on slip spider (28), described slip spider (28) and described righting block (27) spiral shell Stricture of vagina connects；

Described sealing mechanism (3) includes packing element, cone (31) and central canal, and described packing element is set in described On central canal, threaded with described cone (31) in the lower end of described central canal, described cone (31) with Described changement (2) connects；

Described central canal includes exterior central tube (32) and inner central tube (33), and described packing element includes outer packing element (34) With interior packing element (35), described outer packing element (34) is set on described exterior central tube (32), and against described The top of cone (31) is arranged, and described interior packing element (35) is set on described inner central tube (33), and It is connected with described exterior central tube (32).

Drawing type packer the most according to claim 1, it is characterised in that: described joint (1) Upper end is connected with described guiding headstock (26) by described central canal, and described slips (24) is against described cone The bottom of body (31) is arranged.

Drawing type packer the most according to claim 1 and 2, it is characterised in that: described drawing type seals Also include that anti-flushing well mechanism (4), described anti-flushing well mechanism (4) include valve gap (41), spring (42) every device With ball valve (43), described valve gap (41) is connected with described ball valve (43) by described spring (42), and Described valve gap (41), described spring (42) and described ball valve (43) are arranged at described inner central tube (33) In.

Drawing type packer the most according to claim 3, it is characterised in that: described outer packing element (34) There is sealing (341) and supporting part (342), described sealing (341) and described exterior central tube (32) Between outer packing element internal ring (36) is set.